Steering column for a motor vehicle

ABSTRACT

A steering column for a motor vehicle includes a support unit connectable with the chassis of the motor vehicle, a securement part disposed between the side jaws of the support unit, a setting unit disposed between the side jaws of the support unit; a counter-securement part connected with the setting unit; and a clamping mechanism. The clamping mechanism is operably engaged with the setting unit such that in the opened state of the clamping mechanism the setting unit is displaceable with respect to the support unit at least in a longitudinal direction of the steering column, and in the closed state of the clamping mechanism the setting unit is secured at a set position with respect to the support unit. In the event of a motor vehicle crash, the counter-securement part is shiftable with respect to the setting unit with the consumption of energy.

This application is a continuation of application Ser. No. 12/820,319,filed Jun. 22, 2010, which is a continuation application ofInternational application PCT/EP2008/009794, filed Nov. 20, 2008, theentire disclosure of which is incorporated herein by reference.

BACKGROUND OF THE INVENTION

a) Field of the Invention

The invention relates to a steering column for a motor vehicle, which isadjustable at least in its longitudinal direction, comprising a supportunit connectable with the chassis of the motor vehicle, a setting unitdisposed between the side jaws of the support unit, and a clampingmechanism. In the opened state of the clamping mechanism, the settingunit is displaceable with respect to the support unit at least in thelongitudinal direction of the steering column and, in the closed stateof the clamping mechanism, the set position of the setting unit withrespect to the support unit is secured in position. The clampingmechanism comprises a clamp bolt which penetrates openings in the sidejaws of the support unit, and during the opening and closing of theclamping mechanism is rotated about its axis. At least one securementpart is provided between the side jaws of the support unit and displacedthrough the rotation of the clamp bolt during the opening and closing ofthe clamping mechanism, which in the closed state of the clampingmechanism engages into a counter-securement part connected with thesetting unit, or at least during the dislocation beginning in the eventof a motor vehicle crash of the setting unit with respect to the supportunit comes into engagement with the counter-securement part and which,in the opened state of the clamping mechanism, is spaced apart from thecounter-securement part.

b) Description of Related Prior Art

Adjustable steering columns serve to adjust the position of the steeringwheel to the seating position of the driver and are known in variousembodiments. Apart from adjustable steering columns which are onlyadjustable in length or height and inclination direction, respectively,steering columns are known which are adjustable in length as well asalso height and inclination direction, respectively. Such adjustablesteering column is, for example, disclosed in EP 0 802 104 A1. In theopened state of the clamping mechanism, a setting unit, pivotablysupporting the steering spindle, is, with respect to achassis-stationary support unit, displaceable in the direction of alength adjustment as well as also in the direction of a height orinclination adjustment of the steering column. To increase the holdingforces in the closed state of the clamping mechanism, the clampingmechanism comprises intersecting (lamella) disk packs cooperating in themanner of a lamella coupling.

Several arrangements have already been proposed for adjustable steeringcolumns to provide, in the event of a crash of the motor vehicle, anadditional holding force against a dislocation of the setting unit withrespect to the support unit in order to prevent the uncheckeddisplacement of the steering column whereby, under control through anenergy absorption device of the steering column, energy absorption isalso made possible. Such an energy absorption device is configured suchthat, for example, the support unit is realized in the manner of acarriage which is shiftably supported on a chassis unit rigidly disposedon the motor vehicle chassis, wherein between the chassis unit and thesupport unit an energy absorption device, for example a flexural strip,is formed.

Such an implementation is disclosed in WO2006042604. An adjustablesteering column is introduced here, in which for the energy consumptionduring the dislocation of the holding part which pivotably supports thesteering spindle, with respect to the support panel secured on the motorvehicle, a flexural plate bent in the shape of a U is provided which, inthe event of a crash, effects the energy absorption by bending andthrough the additional tearing-open along notchings provided for thispurpose. In order for the energy absorption to take place, in fact, viathese notchings, it is, however, necessary to ensure that the adjustablesteering column does not become dislocated within the scope of thepossible adjustment range. For this purpose ,the securement device withwhich the desired position is arrested after an adjustment must beappropriately laid out. According to WO2006042604, an additional crashblocking device is provided for this purpose. A clamping wedge isprovided which, in the event of a crash, is slid into a gap between thesetting unit and the support unit. The clamping wedge is connected withthe clamp bolt or with a part jointly moved axially together. During theclosing of the clamping mechanism, this is axially shifted together withthe clamp bolt such that a contact face of the clamping wedge comes intocontact on a contact face of the setting unit in order for the clampingwedge in the event of a crash during the onsetting dislocation of thesetting unit to be entrained by the latter.

DE 10 2005 052 123 B3 further discloses an energy absorption device forthe absorption of energy in the event of a crash, in which an arrestelement disposed on the setting unit with which, in the closed state ofthe securement device serving for the securement of the set position ofthe steering column, a counter-arrest element is in engagement is soconnected that in the event of a crash it is shiftable with theabsorption of energy in the longitudinal direction of the steeringcolumn with respect to the setting unit. A further arrest element of asecurement device shiftable with respect to the setting unit with theabsorption of energy is disclosed in EP 1 464 560 A2.

U.S. Pat. No. 6,139,057 A discloses an adjustable steering column of thetype described in the introduction. On the clamp bolt is disposed asecurement part which, through the rotation of the clamp bolt, is turnedduring the opening and closing of the clamping mechanism, wherein aspring-elastic element acts between the clamp bolt and the securementpart. In the closed state of the clamping mechanism, a toothing of thesecurement part engages into a toothing of a counter-securement partwhich is formed by a frame welded onto the inside of a side jaw of thesetting unit. In the opened state of the clamping mechanism the toothingof the securement part is raised off the toothing of thecounter-securement part. Through this arrangement, an additional holdingforce is applied against a longitudinal displacement of the steeringcolumn in the event of a motor vehicle crash. An arrangement is providedacting analogously in the event of a crash against the displacement ofthe height or inclination setting. Through the arrangement disclosed inthis publication the requisite installation space of the steering columnis enlarged and the tooth widths of the cooperating toothings can onlybe implemented such that they are relatively small whereby theadditional holding force of the crash blocking arrangement is limited.

US 2006/009 0586 A1 discloses a similarly acting crash holdingarrangement which acts only against a displacement of the steeringcolumn in the height or inclination direction.

BRIEF SUMMARY OF THE INVENTION

The present invention addresses the problem of providing a steeringcolumn of the type described in the introduction, which, at animplementation with relatively low installation space, in the event of acrash makes possible the reliable engagement of the securement part intothe counter-securement part. This is attained according to the inventionthereby that the counter-securement part is disposed on a wall parallelto the axis of the clamp bolt of the setting unit, or is formed by it.

Because the counter-securement part is disposed on a wall, locatedparallel to the axis of the clamp bolt, in particular of the upper orlower side wall of the setting unit or is formed by it, at aspace-saving realization of the steering column. Nevertheless, arelatively large engagement width between the securement part and thecounter-securement part can be realized. During the opening and closingof the clamping mechanism which, in the closed state, counteracts adisplacement of the setting unit with respect to the support unit, theclamp bolt is turned about its axis and with it the securement partdisposed preferably on or at the clamp bolt. In the opened state, thesecurement part is spaced apart from the counter-securement part, thusis brought out of engagement. In the closed state of the clampingmechanism, the securement part is, preferably resiliently, brought intocontact with the counter-securement part.

In a preferred embodiment, the securement part engages into thecounter-securement part after the closing of the clamping mechanismeither directly under form closure or the securement part is initiallyonly under frictional closure in contact with the counter-securementpart. In the latter case through the resilient contact the securementpart at a beginning dislocation of the setting unit with respect to thesupport unit, as can occur for example when the holding force of theclamping mechanism is exceeded, for example in the event of a motorvehicle crash, is, however, brought into engagement with thecounter-securement part under form closure. The maximal value of thepossible dislocation until reaching the form-closure engagement can bedefined. For this purpose into the counter-securement part canadvantageously be worked several engagement elements, in the simplestcase cutouts, into which a form element, for example a nose, of thesecurement part can engage. The interspace of the cutouts defines themaximal possible shifting path up to the form-closure engagement betweensecurement and counter-securement part.

It is herein of advantage that a multiplicity of feasibilities knownwithin prior art can be applied for the formation of the clamping andgripping mechanism or of the clamping mechanism, with which the supportunit is locked with respect to the setting unit. The locking can takeplace via a form closure, for example via a toothing, as well as alsovia a frictional closure. The activation of the clamping mechanism canalso occur via the known combination of wedge disk and cam part or alsovia rolling bodies, which roll along predetermined tracks and whichpermit the appropriate tightening of the clamping system. Decisive isthat a clamp bolt is provided which is oriented transversely to theshifting direction of the setting unit with respect to the support unitand, upon a change from the position in which the shifting of thesupport unit is made possible with respect to the setting unit, into theposition in which the shifting of the support unit with respect to thesetting unit is blocked, executes a rotational movement about its ownaxis. This rotational movement is utilized for displacing the securementpart into the ready position or out of the ready position.

An advantageous embodiment of the invention provides that, in the eventof a crash, the counter-securement part is shiftable with respect to thesetting unit with the consumption of energy. There is thus a connection,shiftable with the absorption of energy, of the counter-securement partwith the setting unit. The force counteracting the shifting is hereinmuch larger, preferably more than one order of magnitude larger, thanthe conventional force required for the longitudinal displacement of thesetting unit with respect to the support unit in the opened state of theclamping mechanism. If, in the event of a crash, the holding force ofthe clamping mechanisms is overcome and onto the counter-securement parta force acts which exceeds that counteracting the shifting of thecounter-securement part, the counter-securement part can be shifted withrespect to the setting unit with the consumption of energy. Thecounter-securement part and the setting unit are consequently separateparts in this embodiment.

The connection of the counter-securement part with the setting unitshiftable with the consumption of energy is preferably so laid out thatthe forces counteracting a shifting of the setting unit with respect tothe chassis-stationary support unit or the vehicle chassis are in therange of 500 N to 10,000 N. Through these forces potentially furtherprovided holding forces—in particular acting under frictional closure—ofthe clamping mechanism are also overcome. If the forces are within thisorder of magnitude, the risk of injury to the driver is minimized.Special predetermined or settable force courses over the shifting pathare herein desired for optimization, which, in the ideal case, can evenbe settable during the crash.

In an advantageous embodiment, the counter-securement part is, forexample, realized as a U-shaped bent sheet metal element with twoshanks. After installment, the position of the sheet metal element isoriented such that the arc-form section of the sheet metal element isdisposed in the direction toward the driver or toward the steeringwheel-side end of the steering spindle. A first shank, also denoted asplate, is realized as a sheet metal strip and comprises severalengagement elements. A second shank is connected with the setting unit,which directly or indirectly pivotably bearing-supports the steeringspindle and includes two weakening lines, for example notchings,parallel to one another and to the other shank, between which a tearplate is formed. In case the clamping system is closed and a shifting ofthe setting unit takes place with respect to the support unit, throughthe form closure between an engagement element and the form closureelement the plate is shifted such that the bow section is also shiftedand the tear plate is torn out of the second shank. Through themultiplicity of engagement elements, the force-path course and theentire path available for the energy consumption are always identicalindependently of the displacement position of the setting unit withrespect to the support unit. Instead of a tear plate, a pure flexuralplate or a combination thereof could also be provided.

This preferred embodiment entails a number of advantages. For example,additional installation space is hardly required. In particular, theclamp bolt does not need to be extended and the steering column does notneed to be built wider. The engagement into the clamping system is alsominimal and the mounting is simple. With the aid of this embodiment, twofunctions are combined. In the prior art, for example in WO2006042604A1, between the setting unit and the support unit a carriage isprovided. For ease of adjustment of the steering column the setting unitis displaced with respect to the carriage. For the energy absorptionunder control in the event of a crash the carriage is shifted withrespect to the support unit via interspaced energy absorption means. Itmust herein be ensured that during the energy absorption no uncheckedshifting of the setting unit with respect to the carriage takes place.In the embodiment of the invention both functions are combined in oneelement, the U-shaped bent sheet metal element. A carriage, at least forpurely longitudinally adjustable steering columns, is furthermore notrequired.

A steering column according to the invention can be only longitudinallyadjustable or, additionally, also in height or inclination for thelongitudinal adjustability. The clamp bolt can, for example, for thispurpose penetrate elongated holes in the side walls of the support unit,which extend in the direction of the height or inclination adjustment.It is also conceivable and feasible that an intermediate unit isprovided which is adjustable with respect to the support unit in thedirection of height or inclination adjustment, wherein the setting unitis displaceable with respect to the intermediate unit in thelongitudinal direction of the steering column or steering spindle. Suchdesigns are known. In another embodiment the intermediate unit can beomitted and the side jaws of the support unit in the closed state of theclamping mechanism can be directly clamped together with the settingunit, as is also already known.

In a feasible embodiment, the support unit is rigidly secured on thechassis of the motor vehicle. In another embodiment the support unit isheld on a chassis unit which, in turn, is rigidly securable on thechassis of the motor vehicle, wherein it is nonshiftable in normaloperation with respect to the chassis unit. In the event of a crash(=when a threshold value of the acting force is exceeded) it isshiftable with respect to the chassis unit in the direction toward thefront of the motor vehicle. Advantageously energy-consuming means, forexample at least one flexural strip, can herein be provided between thesupport unit and the chassis unit. Such designs are known.

BRIEF DESCRIPTION OF THE DRAWINGS

Further advantages and details of the invention will be described in thefollowing in conjunction with the enclosed drawing, in which:

FIG. 1 is a first embodiment of a steering column according to theinvention in oblique view,

FIG. 2 is an oblique view of the clamp bolt with a securement partdisposed thereon,

FIG. 3 is an oblique view of the counter-securement part,

FIG. 4 shows the securement part disposed on a clamp bolt in engagementwith the counter-securement part,

FIG. 5 shows a portion of the steering column in side view, partiallycut, in the closed position of the actuation lever,

FIG. 6 is a view corresponding to FIG. 5, however in the open positionof the actuation lever,

FIG. 7 is an oblique view of a steering column according to a secondembodiment example of the invention,

FIGS. 8a and 8b are oblique views of the clamp bolt with the securementpart according to this second embodiment of the invention,

FIG. 9 is an oblique view of the counter-securement part,

FIG. 10 shows the securement part disposed on the clamp bolt inengagement with the counter-securement part,

FIGS. 11 and 12 are side views of portions of the steering columnaccording to the second embodiment, partially cut, in the closed andopen position of the actuation lever,

FIG. 13 shows a portion of an oblique view of a steering columnaccording to a third embodiment, a portion of the setting unit beingomitted for the sake of clarity, and the counter-securement part cut inthe longitudinal center,

FIG. 14 shows a portion of an oblique view of a steering columnaccording to a fourth embodiment,

FIG. 15 is an oblique view of a steering column according to a fifthembodiment,

FIG. 16 shows a portion of a side view of the steering column accordingto this fifth embodiment, partially cut,

FIG. 17 is a top view onto the steering column according to the fifthembodiment,

FIG. 18 is an oblique view of a counter-securement part according to amodified embodiment,

FIG. 19 is an oblique view of a counter-securement part according to afurther, modified embodiment,

FIG. 20 is an oblique view of a counter-securement part according to afurther, modified embodiment,

FIG. 21 shows a portion of an oblique view of a steering columnaccording to a variant of the third embodiment, a portion of the settingunit being omitted for the sake of clarity, and the counter-securementpart cut in the longitudinal center.

DESCRIPTION OF PREFERRED EMBODIMENTS

A first embodiment of a steering column according to the invention isdepicted in FIG. 1 to FIG. 6, with FIGS. 2 and 4 illustrating variantsof the clamp bolt 12 to this embodiment.

The steering column comprises a support unit 1 securable on the chassisof a motor vehicle. A steering spindle 2, on whose steering wheel-sideend 3 a steering wheel is attachable, is pivotably bearing-supported bya jacket unit or setting unit 4, which is supported by the support unit1. In the opened state of a clamping mechanism 5 the steering column isadjustable in its longitudinal direction 6 (=axial direction of thesteering spindle 2) and in the direction 7 of the height or inclination.The setting unit 4 is herein displaceable with respect to the supportunit 1 in the longitudinal direction 6 and in the direction 7 of theheight or inclination adjustment.

The setting unit 4 is disposed between side jaws 8, 9 of the supportunit 1 in openings 10, 11, which are realized in the form of elongatedholes extending in the direction 7 of the height or inclinationadjustment and through which penetrates a clamp bolt 12 of the clampingmechanism 5. The clamp bolt 12 penetrates further openings 13, 14 inside jaws 15, 16 of the setting unit (4), which extend in the form ofelongated holes in the longitudinal direction 6.

The clamp bolt 12 is held by the margins of the openings 10, 11penetrated by it in the side jaws 8, 9 of the support unit 1nonshiftable in the particular set height or inclination position of thesteering column in the longitudinal direction of the steering column.

Between the support unit 1 and the setting unit 4 in the depictedembodiment is disposed an intermediate unit. This includes side jaws 41,42 which are disposed between the particular side jaw 8, 9 of thesupport unit 1 and the setting unit 4. The clamp bolt 12 penetratesround holes in the side jaws 41, 42. The intermediate unit isswivellable with respect to the support unit 1 about a swivel axis 30 inthe direction 7 of the height or inclination adjustment. In thelongitudinal direction 6 of the steering column, the side jaws 41, 42are guided with respect to the setting unit 4 through projecting webswhich engage into longitudinal grooves 43 on the side faces of thesetting unit 4.

In the closed state of the clamping mechanism, the side jaws 8, 9 of thesupport unit 1 are clamped on both sides against the side jaws 41, 42 ofthe intermediate unit and this is clamped against the setting unit 4,wherein the cooperating friction faces represent arrest elements of theclamping mechanism acting under frictional closure. Press-on parts 17disposed on the clamp bolts and pressed against the outside of the sidejaws 8, 9 form further friction faces cooperating with the side jaws 8,9, whereby further arrest elements of the clamping device acting underfrictional closure are formed. It is conceivable and feasible inprinciple to provide further friction faces through cooperating lamella,as is known.

To open and close the clamping mechanism serves an actuation lever 18through the swivelling of which in a known manner a cam disk 20cooperating with a counter disk 19 (=wedge disk) is turned, whereinduring the closing of the clamping mechanism the two disks 19, 20 arespread apart.

The arrest elements of the clamping mechanism 5 are thus brought intoengagement with one another through an axial shifting of the clamp bolt12 or through an axial shifting with respect to the clamp bolt 12.

Instead of an actuation lever 18, another actuation, for exampleelectric actuation, of the clamping mechanism could also be provided.Instead of a wedge or cam disk 20, another mechanism for the axialshifting of the clamp bolt 12 or for the axial shifting of arrestelements with respect to the clamp bolt 12 could also be provided.

The actuation lever 18 is connected torsion-tight with the clamp bolt 12by means of a surface projection 21 formed as a polygonal of theclamping bolt 12, as is illustrated in FIG. 4. The actuation lever 18for the torsion-tight connection with the clamp bolt 12 could, instead,also mate over the bolt head 22 of the clamp bolt 12. It could be weldedtogether with the clamp bolt 12 or be connected via a roller-burnishingor a knurling on the clamp bolt 12 through a press fit. A correspondingclamp bolt 12 without additionally realized surface projection 21 isillustrated in FIG. 2.

Through the torsion-tight connection of the actuation lever 18 with theclamp bolt 12, it is rotated about its axis during the opening andclosing of the clamping mechanism.

On the clamp bolt 12 is disposed a securement part 23. It is located inthe region between the side jaws 8, 9 of the support unit 1. Thesecurement part 23 is advantageously disposed on the clamp bolt 12swivellably with respect to the clamp bolt 12 about the latter's axisthereby that, as depicted, the clamp bolt 12 penetrates through anopening in the securement part 23.

On the clamp bolt 12 is further disposed a spring element 24.Bilaterally to the securement part 23, this comprises sections 24 a, 24b encompassing the clamp bolt 12 in the manner of a coil spring, and abow section 24 c connecting these, wherein the sections 24 a, 24 b, 24 care comprised of a continuous spring wire. Sections 24 a, 24 b arenonrotatably connected with the clamp bolt 12, for examplegrip-fittingly, through form closure or through material closure, forexample adhesion or spot welding. The bow section 24 c extends through achannel 25 in the securement part 23.

Without external force being exerted, the securement part 23 is therebyheld in a certain angular position with respect to the clamp bolt 12 andcan be deflected out of it against the reset force of the spring element24.

On the setting unit 4 is further held a counter-securement part 26specifically on the upper side wall 27 of the setting unit 4, which wallis parallel to the axis of the clamp bolt 12. The counter-securementpart 26 includes a plate with a multiplicity of engagement elements 29successively spaced apart at a particular distance in the longitudinaldirection 6 of the steering column or steering spindle 2. Theseengagement elements 29 are provided for the engagement under formclosure of the securement part 23. In the depicted embodiment examplethese engagement elements 29 are formed by slot-form cutouts through thematerial of the plate, into which a projecting nose 31 of the securementpart 23 can be inserted. The cutouts could also be realized for examplein the form of groove-like indentations or simply as punched holes.

In the opened state of the clamping mechanism 5, the securement part 23is raised off the counter-securement part 26, cf. FIG. 6. Through theturning of the clamp bolt 12 during the closing of the clampingmechanism 5, the securement part 23 is pressed onto thecounter-securement part 26. Two cases can occur herein. On the one hand,the mutual position between securement part 23 and counter-securementpart 26 (due to the instantaneous set position of the steering column inthe longitudinal direction) can currently be such that the securementpart 23 engages into one of the engagement elements 29 such that aform-closure engagement between the securement part 23 and thecounter-securement part 26 is realized immediately. On the other hand,the nose 31 can come to rest on a web between two successive engagementelements 29. In this case the securement part 23 is pressed through thespring force of the spring element 24 against the counter-securementpart 26. Should in the last-described position of the securement part 23a vehicle crash occur through which the holding force, effected by thearrest elements of the clamping mechanism 5, of the setting unit 4 isexceeded with respect to the support unit 1, a shifting of the settingunit 4 with respect to the support unit 1 would begin until the nose 31arrives in the region above an engagement element 29, whereupon it isbrought into engagement with the engagement 29 through the spring forceof the spring element 24.

Either immediately after the closing of the clamping mechanism 5 or atleast after an initially minimal shifting of the setting unit 4 withrespect to the support unit 1, which is smaller than the interspace oftwo successive engagement elements 29, in the event of a crash aform-closure engagement of the securement part 23 with thecounter-securement part 26 occurs.

In the embodiment example according to FIGS. 1 to 6, thecounter-securement part 26, realized in the form of a plate, isconnected with the setting unit 4 in such manner that with theconsumption of energy is shiftable with respect to the setting unit 4 inthe longitudinal direction 6 of the steering column or of the steeringspindle 2. For this purpose, one shank of the U-shapedcounter-securement part 26 is connected via a recurvation with a tearplate 32, which, in turn, is rigidly connected with the side wall 27 ofthe setting unit 4. The tear plate 32 could also form a section of theside wall 27 of the setting unit 4.

The tear plate 32 comprises weakening lines 33, 34, formed for exampleby punch-ins, which are indicated in FIGS. 3 and 4 by dashed lines.Thereby a tear plate 28 is delimited. Through a sufficiently strong pullon the plate-shaped counter-securement part 26 the tear plate 28 can beprogressively torn off along the weakening lines 33, 34 with thedissipation of energy, wherein a plate is formed which continues theplate-like counter-securement part 26. A further fraction of energydissipation occurs through the bending work performed in the shifting ofthe site of the recurvation.

Instead of forming weakening lines 33, 34, the plate 28 a can at leastbe partially realized as a flexural plate, which is separated from thebase plate 32 a by slots or elongated holes 33 a, 34 a in apredetermined bending region (cf. FIG. 18).

It is moreover conceivable and feasible to combine the two energyabsorption mechanisms and to provide, adjoining the elongated holes 33a, 34 a, corresponding weakening lines 33, 34, which make possible thecontrolled tearing open of the tear plate 28 after terminating the purebending operation of the plate 28 a (FIG. 19).

As illustrated in FIG. 20, such energy absorption elements can also bedisposed parallel on a base plate, wherein at each energy absorptionelement pure bending formings or bending formings with adjoiningmaterial removal/tearing operations or pure tearing operations can beprovided and with the discrete energy absorption elements identical ordifferent energy absorption mechanism can be employed. It is hereinfeasible to provide two energy absorption elements or several energyabsorption elements parallel on a single tear plate 32 or base plate 32a or on separate tear or base plates disposed one next to the other.

A second embodiment example of the invention is depicted in FIGS. 7 to12. The difference from the previously described embodiment examplecomprises primarily the type of connection of the securement part 23with the clamp bolt 12. The securement part 23 is again disposedswivellably on the clamp bolt 12. The clamp bolt is provided with a pin35 radially projecting outwardly, which engages into a slot 36 in thesecurement part 23 and, during a swivelling of the securement part 23with respect to the clamp bolt 12, becomes shifted therein. Further isdisposed on the clamp bolt 12 a spring element 37 in the form of a bowspring, wherein ends of the spring wire project into radial bores of theclamp bolt 12. In the closed state of the clamping mechanism 5 thespring element 37 extending over the securement part 23 presses thesecurement part 23 against the counter-securement part 26 (cf. FIGS. 10and 11). When the clamp bolt 12 is rotated during the opening of theclamping mechanism 5 (in the clockwise direction viewed from the endopposite the bolt head 22) the pin 35 is jointly swivelled and abuts anend of slot 36 (this is located in FIG. 8b minimally beneath pin 35),whereupon the securement part 23 is swivelled and raised from thecounter-securement part 26.

Other connections of the counter-securement part 26 with the settingunit 4 are also conceivable and feasible, through which thecounter-securement part 26 is shiftable in the event of a motor vehiclecrash with the consumption of energy with respect to the setting unit 4.FIG. 13 shows by example an embodiment in which on the side of thecounter-securement part 26 facing away from the securement part 23 abolt 38 is disposed which extends into an elongated hole 39, extendingin the longitudinal direction 6, in the side wall 27 of the setting unit4. In the starting state the bolt 38 is in an enlarged region of theelongated hole 39. With a shifting of bolt 38 with respect to theelongated hole 39 a widening of the elongated hole 39 occurs, wherebyenergy is consumed.

In a variant of this embodiment, which is illustrated in FIG. 21, theelongated hole 39 is adjoined by a strip region 39 a, which is separatedwhen the bolt 38 is run in. In this manner in a first section a firstenergy absorption level by means of the widening of the elongated hole39 can be specifically set and, in a second section, a second energyabsorption level by means of the separation of the strip region 39 a. Itis also possible to vary the width of the elongated hole over theshifting path of the bolt according to the desired course of the energyabsorption. The width can thus, for example, be decreased continuouslytoward the end of the crash path in order to attain a progressive energyabsorption.

The strip region 39 a can alternatively also be represented as anelongated hole with very narrow width, for example less than half of thediameter, or the thickness, of bolt 38.

It is also conceivable and feasible to omit the widening of an elongatedhole 39 entirely and to represent the energy absorption exclusivelythrough the separation of a strip region 39 a. On the top and/orunderside of the strip region 39 a a longitudinal groove isadvantageously disposed. The groove is dimensioned appropriately interms of depth and/or width for the setting of the energy absorptionlevel.

If no energy-dissipating shifting of the setting unit 4 with respect tothe support unit 1 in the event of a crash is desired, but rather anadditional holding force is to be attained, the counter-securement part26 can be connected rigidly with the side wall 27 of the setting unit 4or be directly formed by it. An embodiment of a latter realization isdepicted in FIG. 14. The engagement elements 29 are here disposeddirectly in the side wall 27.

In the embodiment example depicted in FIGS. 15 to 17, the U-shapedcounter-securement part 26 encompasses the securement part 23. Thesection including the engagement elements 29 is located in contact onthe upper side wall of the setting unit 4. The tear plate with the tearplate 28 is secured on the setting unit 4 on the side of the clamp bolt12 facing away from the steering spindle.

Instead of a tear plate 28, again, a flexural plate or a combination ofa flexural and tear plate, for example, could be provided.

In the several, previously described embodiments, each of thecounter-securement parts 26 is disposed on the upper side wall 27 of thesetting unit 4 or is formed by it. Instead, the counter-securement partcould also be disposed on another wall of the setting unit 4 disposedparallel to the axis of the clamp bolt 12 or be formed by it, forexample by the lower side wall.

The engagement elements 29 of the counter-securement part 26 could alsobe realized in the form of cutouts, wherein the securement part has anadapted engagement element in order to make possible the nonshiftableengagement, especially the form-closure engagement, with respect to thelongitudinal direction 6 of the steering column or steering spindle 2,between the securement part 23 and counter-securement part 26. Hereinwould again be provided a multiplicity of engagement positions for thesecurement part 23 in the longitudinal extension, extending in thelongitudinal direction 6, of the counter-securement part 26. Theengagement elements 29, for example, of the counter-securement part 26,could also be formed by teeth of a toothing, and the securement part 23could be realized with a corresponding counter-toothing.

The intermediate unit 40, provided in the depicted embodiments betweenthe support unit 1 and the setting unit 4, could also be omitted. Theside jaws 8, 9 of support unit 1 could in this case be pressed on bothsides directly against the setting unit 4 when the clamping mechanism 5is in its closed state. The swivel axis between the setting unit 4 andthe support unit 1 could in this case also be formed, for example, by auniversal joint via which the steering spindle 2 is connected with afurther section of the steering spindle. This swivel axis could,furthermore, also be formed by a swivel bolt disposed on the supportunit 1, which penetrates an elongated hole, extending in thelongitudinal direction 6, of the setting unit 4.

The invention can also be employed in steering columns which are onlyadjustable in the longitudinal direction 6. The clamp bolt 12 could inthis case penetrate through openings 10, 11, realized in the form ofround holes, in the side jaws 8, 9 of the support unit 1.

The sections of the side jaws 15, 16, projecting beyond the upper sidewall 27, of the setting unit 4 could also be omitted such that the clampbolt 12 does not penetrate openings 13, 14 in the setting unit 4.

It would also be conceivable and feasible to connect the securement part23 nonswivellably with the clamp bolt 12 and which itself is, forexample, spring-elastically realized. Moreover, an embodiment could, forexample, be provided in which a securement part 23 is nonswivellablyconnected with the clamp bolt 12 and during the opening and closing ofthe clamping mechanism 5 a driving element, for example the actuationlever 18, acts directly onto a clamp part, for example the wedge or camdisk 20, and turns it. The clamp bolt 12 could be entrained by the clamppart through its rotation and specifically with the interconnection of aspring element such that the securement part 23 in the closed state ofthe clamping mechanism 5 is pressed by this spring element onto thecounter-securement part 26.

It would further also be conceivable and feasible to provide theengagement elements on an elongated part of the securement part and toprovide on the counter-securement party a nose which engages into theengagement elements.

In all of the described embodiments in which an energy-dissipatingshiftability of the counter-securement part with respect to the settingunit is provided, the shiftability of the counter-securement part withrespect to the setting unit has a defined predetermined or settableforce-path course. With a force acting in the axial direction of thesteering column, which is of such magnitude that a shifting of thecounter-securement part with respect to the setting unit occurs, thesetting unit becomes herein advantageously shifted in the axialdirection of the steering column.

The magnitude of the force acting onto the setting unit in thelongitudinal direction of the steering column in the direction towardthe motor vehicle front, starting at which a shifting of thecounter-securement part with respect to the setting unit occurs, ispreferably less than 10,000 N. It can for example also be less than 5000N.

LEGEND TO THE REFERENCE NUMBERS

-   1 Support unit-   2 Steering spindle-   3 Steering wheel-side end-   4 Setting unit-   5 Clamping mechanism-   6 Longitudinal direction-   7 Direction-   8 Side jaw-   9 Side jaw-   10 Opening-   11 Opening-   12 Clamp bolt-   13 Opening-   14 Opening-   15 Side jaw-   16 Side jaw-   17 Press-on part-   18 Actuation lever-   19 Counter disk-   20 Cam disk-   21 Surface projection-   22 Bolt head-   23 Securement part-   24 Spring element-   24 a Section-   24 b Section-   24 c Bow section-   25 Groove-   26 Counter-securement part-   27 Side wall-   28,28 a Plate-   29 Engagement element-   30 Swivel axis-   31 Nose-   32 Tear plate-   32 a Base plate-   33 Weakening line-   33 a Elongated hole-   33 b Elongated hole-   34 Weakening line-   35 Pin-   36 Slot-   37 Spring element-   38 Bolt-   39 Elongated hole-   39 a Strip region-   40 Intermediate unit-   41 Side jaw-   42 Side jaw-   43 Longitudinal groove

1. A steering column for a motor vehicle, which is adjustable at leastin a longitudinal direction thereof, the steering column comprising: asupport unit connectable with a chassis of the motor vehicle, thesupport unit having side jaws; a securement part disposed between theside jaws of the support unit; a setting unit disposed between the sidejaws of the support unit; a counter-securement part connected with thesetting unit; and a clamping mechanism which has an opened state and aclosed state and which includes a clamp bolt which penetrates openingsin the side jaws of the support unit, the clamp bolt having an axis androtating about the axis during opening and closing of the clampingmechanism, wherein the clamping mechanism is operably engaged with thesetting unit such that in the opened state of the clamping mechanism thesetting unit is displaceable with respect to the support unit at leastin the longitudinal direction of the steering column, and in the closedstate of the clamping mechanism the setting unit is secured at a setposition with respect to the support unit, wherein the securement partis displaced through the rotation of the clamp bolt during the openingand closing of the clamping mechanism, wherein the securement partengages into the counter-securement part in the closed state of theclamping mechanism or comes into engagement with the counter-securementpart during dislocation of the setting unit with respect to the supportunit in an event of a motor vehicle crash, wherein the securement partis spaced apart from the counter-securement part in the opened state ofthe clamping mechanism, wherein the counter-securement part is disposedon or formed by a wall which is parallel to the axis of the clamp bolt,wherein the counter-securement part is connected with the setting unitvia a tear plate or a flexural plate or a combination of a flexural andtear plate, and wherein, in the event of the motor vehicle crash, thecounter-securement part is shiftable with respect to the setting unitwith a consumption of energy by tearing the tear plate or by flexing theflexural plate or by tearing and flexing the combination of the flexuraland tear plate wherein the tear plate or the flexural plate or thecombination of the flexural and tear plate is a U-shaped element withtwo shanks wherein one of the shanks comprises several engagementelements for engaging the securement part into the counter-securementpart.
 2. The steering column of claim 1, wherein the wall which isparallel to the axis of the clamp bolt is a lower or an upper side wallof the setting unit.
 3. The steering column of claim 1, wherein thecounter-securement part comprises a multiplicity of engagement elementsone succeeding another in the longitudinal direction of the steeringcolumn.
 4. The steering column of claim 3, wherein the engagementelements are formed by cutouts into which a projecting nose of thesecurement part can be inserted to secure the setting unit with respectto the support unit in the longitudinal direction of the steeringcolumn.
 5. The steering column of claim 1, wherein in the closed stateof the clamping mechanism the securement part is spring-elasticallypressed onto the counter-securement part.
 6. The steering column ofclaim 5, wherein the securement part is swivellable with respect to theclamp bolt, and a spring element acts between the clamp bolt and thesecurement part.
 7. The steering column of claim 1, wherein thecounter-securement part is connected with the setting unit via at leastone bolt which engages into an elongated hole, and wherein a hole widthof the elongated hole is at least partially narrower than an outerdiameter of the bolt, whereby in the event of the motor vehicle crashthe bolt is shiftable in the elongated hole with the consumption ofenergy.
 8. The steering column of claim 1, wherein, in the closed stateof the clamping mechanism, the side jaws of the support unit are pressedbilaterally onto the setting unit.
 9. The steering column of claim 1,further comprising an intermediate unit which has side jaws and which isdisposed between the setting unit and the side jaws of the support unit,and wherein, in the closed state of the clamping mechanism, the sidejaws of the support unit are pressed bilaterally onto the side jaws ofthe intermediate unit, which in turn are pressed bilaterally onto thesetting unit.
 10. The steering column of claim 1, wherein the clamp boltis held nonshiftably in the longitudinal direction of the steeringcolumn through margins of the openings in the side jaws of the supportunit.
 11. The steering column of claim 1, wherein shifting of thecounter-securement part with respect to the setting unit begins at aforce, acting in the longitudinal direction of the steering column ontothe setting unit, which is less than 10,000 N.
 12. The steering columnof claim 1, wherein the other one of the shanks is connected with thesetting unit.
 13. The steering column of claim 1, wherein the U-shapedelement comprises an arc section connecting the two shanks, wherein thetwo shanks project from the arc section in a direction to a steeringwheel-side end of the steering column.
 14. The steering column of claim1, wherein the U-shaped element comprises an arc section connecting thetwo shanks, wherein the two shanks are closer together than an outerdiameter of the arc section.
 15. The steering column of claim 1, whereinthe tear plate or the flexural plate or the combination of the flexuraland tear plate is a sheet metal element.